First collision dose

• Representative of the absorbed dose when the mean free path is large compared to the target.

• Expressed as dose delivered per individual neutron

• Units are those of dose per neutron/cm²(Gy cm²)

N = atom density (cm^-3)

σ_S= scattering cross section (for each element)

Q_ave= average energy transferred in collision (½E_max)

ρ = tissue density

57. Сalculation of heavy ions protection. A track structure model for the calculation of inactivation probabilities of heavy ions has been developed, which is based on measurable quantities only. The model describes the following inactivation properties of heavy ion radiation: (1) the transition from shouldered to exponential survival curves, depending on the atomic number, energy and LET of the particle; (2) the LET dependence of inactivation cross sections s, including the supralinear increase for low LET particles, the plateau region between 200 and 1000 keV.µm-1 and the s LET hooks for higher LET values; (3) differences in the shape of the s LET hooks for different biological objects; (4) the shift of RBE maxima from 30 to 300 keV.µm-1 with increasing atomic number; (5) the exchanged efficiency of heavy ions in the case of mixed radiation fields (X rays combined with heavy ion irradiation).

вопросы

1. The basic definition of interaction of ionizing radiation with matter

2. The biology influence of ionization radiation

3. Radiation sickness

4. The radioactivity law

5. The activity of radionuclides

6. The unit of measurement

7. Protons, alpha particles and heavy ions

8. Ionization loses

9. Elastic and inelastic scattering of heavy charge particle

10. Multiple scattering of the recoil of heavy charge particle

11. Nuclear reactions